Folding ladder



P. ZEMAN FOLDING LADDER Nova 19, 1935.

Filed April 30, 1935 2 Sheets-Sheet 2 INVENTOR PA UL. Z EMAN 4; ATTORNEYPatented Nov. 19, 1935 UNITED STATES PATENT OFFICE 3 Claims.

My invention relates to improvements in folding step ladders and has foran object to provide a collapsible and foldable step ladder which is ofstrong and durable construction. Another object is to provide acollapsible step ladder which may readily be extended either to its fullextent making available for use every step of its complement of steps,or may be extended to a lesser degree, bringing into operative positionone or more steps as occasion may require.

Another object of the invention is to so arrange the parts of a foldingstep ladder that when the front and back portions are spread apart eachwill present a series of steps, a further object being to form suchparts as collapsible and extensible members.

Another object of the invention is to so form the front and rearportions of a duplex ladder that these portions may be reassembled as adouble length extension ladder.

A further object of the invention is toprovide an extensible andcontractible tension cable for holding the parts of an extension ladderfirmly in its various positions of adjustment.

In the drawings accompanying this specification and forming part of theapplication, I have illustrated one practicable form of the invention,which at the present time may be regarded as the preferred form, inwhich drawings,

Fig. 1 is a front view of a ladder made in accordance with my invention,the side frames being shown as collapsible and the steps as folded;

Fig. 2 is a side elevation of the device shown in Fig. 1. In this viewthe front and rear members of the ladder are shown folded together.

Fig. 3 is a view taken at about the plane 3-3 of Fig. 2 looking down.

Fig. 4 is a longitudinal section of two of the telescoping membersshowing one of the steps partly broken away and the holding dog inposition.

Fig. 5 is an end View of the ladder showing the front and rear portionsextended and the ladder sections drawn out so these are extended rep--resenting the step ladder in its normal complete height and Fig. 6 is aview on a smaller scale showing the manner in which the front and rearmembers of the ladder may be connected together in one continuous ladderof the straight ladder type.

The ladder in the form illustrated comprises what might be termed frontand rear ladder portions 1 and B which are joined together at the upperportion by means of a head member 9 which carries the top step orplatform Ill. The

front and rear members are shown provided with spreading feet II and I2for resting upon the ground or floor when the ladder is in use or storedin an operative position.

The front and rear sections are shown'as each 5 made up of a number oftelescoping members, each carrying a step. In the illustration there areshown five. of these telescoping members which may be designated by thereference character [3, the lowermost of which has secured to 10 it thefeet II and i2. The upper element I4 of the front ladder portion is madefast with the head member 9 and platform step I0; the upper member [5 ofthe rear ladder portion is shown pivoted to the head member 9 by meansof a removable pin 16.

In the present illustration there are five steps I! shown for each ofthe front and rear ladder portions. The uppermost of these steps of thefront portion is pivoted to the lower part of the member [4. Thesuccessively lower steps are carried by the lower ends of the variousmembers 1.

Associated with each of the steps I! is a pivoted dog l8 which ispressed into its upper posi- 5 tion by means of a spring I9 and passesthru a slot 20 formed in the telescoping members. The pivot 2! for thestep and the dog passes thru the side of the telescoping member.

Each of the members 1 is formed with a longitudinal slot 22 in which apin 23, carried by the lower part of the section immediately above, maymove. These slots are to permit the extension of the ladder or thesection and to assure that the parts do not over run one another. Itwill 5 be noted that each slot extends upwardly above the normalposition of the parts when in their operative position. This amount ofoverthrow is for the purpose of permitting the operation of the step andthe dog [8 in the movement into and out of operative position.

An extensible and contractible tension cable is provided for the holdingof the parts of the ladder firmly in its various positions ofadjustment. This cable is carried by a spindle 5 or drum member 24 whichhas within it a return spring after the principle of that used in shaderollers. The cable is really formed in two parts, one for each side ofthe ladder and each of the parts is double. By reference to Fig. 1, itwill be seen that the cable at the left hand side is doubled at 25 andthe cable 26 at the right hand side is doubled, both loops being held bya staple 21. By this means when the drum 24 rotates in a windingdirection, the cables are laid on double and each has two extending ends28, 29. Each end of the cable is formed with an eye 30 passing over aheaded pin 3|, carried by the end of the next to the last telescopingunit 1. The front and rear portions 1 and 8 of the ladder are held intheir open position by means of a folding brace 32 pivoted at the frontand back by means of removable pins 33. At the center of this brace 32,there is pivoted a pulley wheel 34. The cable 28 which is at the frontat the top and bottom of the ladder, is placed around the rear of thispulley and the cable 29 at the top and bottom is passed at the front ofthis pulley. When the spring within the roller 24 is of proper strengthsufficient tension is asserted upon the ladder in its various positionsof adjustment to hold the parts steady. When the ladder is in theposition as shown in Figs. 1 and 2 and the user wishes to bring but onestep in position foruse, he may, without releasing the hook 35 whichholds the feet H and 12 together, raise the top step or platform In, asufficient amount to bring the uppermost steps H into a position whereaction of the dog l8 and its associated parts will hold it elevated. Thetension of the cable is then sufficient to hold the parts in thisposition while in use or while being moved from place to place. When theoperator wishes to spread the front and rear portions apart so that thefeet H and I2 rest fiat upon the floor, he merely releases the hook 35and opens these parts. In this position, the uppermost step in the frontand in the rear is in position for use and the top of the platform It!is substantially parallel with the ground. As the operator needsadditional steps for use, he merely has to raise the top platformagainst the tension of the cable operating spring a suflicient distanceto permit the release of the additional steps and the engagement of thedogs I8 in the upper slots.

In Fig. 5 the ladder is shown with all its telescoping sections fullyextended and the front and rear portions open to their fullest extent.In this position there are steps in both the front and rear portions. Ofcourse, if one wishes to use the ladder in the form illustrated in Fig.5 as an ordinary step ladder they are not necessary altho for certainuses step ladders are made with steps or rungs in both the front andrear.

Should the user wish a ladder twice the length of the ladder in the Fig.5 position, he then removes the brace 32 from its illustrated positionand removes the cable from the pins 3!. He then removes the pin is atthe top of the rear section, turns the rear of that section toward thefront and secures its upper portion below the foot H, passing the pin I6thru the hole 36 provided for that purpose. He then fastens therespective ends of the brace 32 to the lower part of what was originallythe front and to the top of the part which was originally the rearsection, making it into a V shape and passes the cable over the pulley34 and secures its eye 30 to the lowermost pin 3|. 5

Having thus described my invention, I claim and desire to secure byLetters Patent:

1. In a collapsible and expansible ladder, the combination with a footmember and a series of members for telescoping with the foot member, 1of a series of steps, there being a step pivoted at its rear portion tothe lower end of each of the telescoping members, a holding dogassociated with each of the steps and extending thru slots formed in thetelescoping members, spring means 15 active upon the dog for raising itinto operative position, the length of the dog being of such proportionin relation to the inside dimension of the telescoping members thatexcept when the dog is opposite the slots provided for it, it and theassociated step are held in a closed position, the organization beingsuch that upon the extension of any two of the members telescoping onewith the other and upon the registering of the slots therein the dogpertinent to those slots extends thru them and holds the associated stepin operative position.

2. In a collapsible and expansible ladder, the combination with a footmember and a series of members for telescoping with the foot member, soof a series of steps, there being a step pivoted at its rear portion tothe lower end of each of the telescoping members, a head member securedto the uppermost of the telescopic members, a spring roller carried bythe head member, a tension cable 35 Wound upon the spring roller andmeans carried by the foot member for the attachment of the cable.

3. In a collapsible and expansible ladder, the combination with a footmember and a series of members for telescoping with the foot member, ofa series of steps, there being a step pivoted at its rear portion to thelower end of each of the telescoping members, a head member secured tothe uppermost of the telescopic members, a top platform step carried bythe head member,

a spring roller carried by the head member, a tension cable wound uponthe spring roller and means carried by the foot member for theattachment of the cable, a holding dog associated with each of thesteps, and extending thru slots. formed in the telescoping members, theorganization being such that upon the extension of any two of themembers telescoping one with the other and upon the registering of theslots therein the dog pertinent to those slots extends thru them andholds the associated step in operative position.

PAUL ZEMAN.

